The long-range purpose of the project is to study the relationship between herpesviruses and human cancer. The topics of present interest are: 1) the mechanism of in vitro cell transformation by herpes simplex virus (HSV) with emphasis on the question of whether HSV acts as a direct oncogen or as a cocarcinogen which alters expression of a cellular gene(s) which serves as the direct oncogen (e.g., endogenous type C virus); and 2) the mechanism of herpesvirus latency as exemplified by persistence of repressed Epstein-Barr virus (EBV) genomes in human cells.